Liquefied-rubber composition and method of making the same



" lNVENTOR 4Q/f Zij Em BY Y ATTORNEYS Feb. 4, 1930. H. P. BUTLER n LIQUEFIED RUBBER COMPOSITION AND METHOD OF MAKING THE SAME Filed May 1o, 1928 lvNl &. I' ,{.......k.in

Patented Feb. 4, l193() UNITED -sTATEs PATE.

HAROLD PAGE BUTLER, or NEW Yox, N, Y.

Application med may 1'o,

This invention relates to a composition of matter and the method of making the same. More specifically this invention relates to a composition of liquefied rubberand a cellulose material, such as'pyroxylin or soluble cotton. y p In my co-pending application, Serial No. 181,932 I have described and claimed a liqueed rubber and method of making the same and in said co-pending application I'have also described a composition comprising the liquefied rubber and soluble cotton or yroxylin. This application is tol be regar ed as a continuation in part of my co-pending appli*` cation, Serial No. 181,932.

One of the objects of his invention is to produce a liquid composition comprising liquefied rubber and cellulose material, such as pyroxylin in soluble form the resulting composition being of a character suitable for application to surfaces by means of a brush or any other Way and also being suitable for admxture with suitable ingredients rendering the product especially suitable for certain 5 specic uses.

As an example of suitable procedure which may be employed in producing my improved composition, a liquelied^rubber may be prepared in accordance with the disclosure of my co-pending application, Serial No. 181,932

and after this liquefied rubber has cooled tol substantially atmospheric temperature, cellu .lose material, such. as soluble pyroxylin or soluble cotton, may be incorporated with the liquefied rubber by simplymixing these constituents together by any means adapted to produce -a uniform mixture of the two liquids.

To further explain the procedure indicatedabove crude rubber may be firsty dissolved in a suitable solvent suchas benzol or toluol t`o which carbon tetrachloride may be e added or not as desired and after the rubber solvent has becomel thoroughly incorporated in the crude rubber the resulting product is heated to a boiling temperature and maintained at this temperature for several hours. This heat treatment should take place in an apparatus of such a character that all of the 5 the, heating operation are returned to the condensable vapors' or gases driven off during` 192s.- seriai No. 276,641.

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mass being heated., This heat treatment can i be conveniently carried out in `a still or retort l ucts which have'been driven oil?l during the heating operation. p In preparing the liquefied rubber according vto the procedure outlined in the preceding paragraph I iindvthat thej most satisfactory results are obtained when the temperature in the retort or kettle is maintained in the neighborhood of 100 to' 120 C., the precise temperature depending upon the nature of the solvent or solvents used in conjunction with the rubber. The heating may becontinued for two and one-half to threehours and as the operation progresses the supply of heat may be decreased so as to reduce the temperature to substantially 100 C.

After the liquefied rubber has been prepared the cellulose material may be iincorporated therewith to produce my improvedl composition. A suitable cellulose preparation such as soluble cotton is mixed directly with the liquefied rubber, preferably after the rubber has cooled to approximately atmospheric temperature. I prefer to stir'the liquefied rubber while slowly adding the cellulose material, the stirring beingcontinued luntil the'mixture becomes uniform' thruout. For example, I may graduallyy add 1/2 pint to 1 pint of soluble pyroxylin to from- 2 to 12 ounces of liquefied rubber while agitating the liquefied rubber and the result-4 ing product is of uniform consistency and of great value as a surfacing or coating compound.y It flows easily, is Waterproof and' strongly adhesive and dries to a fine finish on any surface to which it isapplied. As a furtherexample, to the quantity 'of liquefiedl rubber prepared by utilizing 8 ounces'of crude rubber with 1 gallon of benzol I'subsequent-- ly addapproximately 8 ounces of soluble cotton, the soluble cotton being' added preferably after the liquefied rubber has been thinned to some extent by the additionof a suitable solvent. By adding to the resulting composition one quart of butyl acetate I may obtain about five quarts o f a product thermore, other suitable ingredients may be added to the composition. Various pigments may be added, and if the compositlon 1s to vbe used for coating textiles, suitable solvents, such asnaphtha, kerosene,

' castor oil, linseed oil, et cetera may be incorporated with the solution of liquefied rubbe and cellulose'naterial and suitable fillers such as china clay and lamp black may be -added when desired. My improved composi- `tion4 of liquefied rubber and cellulosev de rivatives may be usedf as a base'from which paints and varnishes can be prepared by adding the necessary ingredients. Thus the liquid composition may be rendered suitable for use as a rubberized and cellulosic paint .'by adding to the composition a dryer, a pigment and a properly treated gumin suitable proportions.

In the accompanying drawings I have illustrated several forms of apparatus suitable for preparing theliquefied'rubber which forms a part my improved composition. In the drawings,

Fig. 1 is a vertical, sectional viewof a double-jacketedkettle and reflux condenser associated therewith; and Fig.Y 2' is a similar view of another form of condenser. y

TheJ mixture of 'rubber and solvent is boiled in a double-jaclsii'eted kettle or still consisting of an inner cohainer 1v preferably provided with a lining 2 of glass. or other suitable inert material. An outer container surrounds the lower portion of the inner container and is spaced therefrom to provide al jacket 4. This jacket is provided with aninlet pipe 5K connected to a mixing valve 6. -A steamand hot I" water pipe 7j iJs con-nected to the mixing valve and a 'cold water pipe Seis also connectedto the mixing valve so that iuid of a desired temperature may be delivered into thejacket.

A thermometer 9 is arranged in the feedpipe 5. The jacket is provided with/an outlet pipe 10 and with a drain; pipe 11 having a valve therein. A hood '12 is arranged over the kettle and isprovided with a window 13 so that the operation of the condenser may be. notedfrom time tov time. .A door 14 is also 'provided in the hood below the window 13.

The lhood is glass lined, like the kettle proper. A reliux condenser 15 is mounted on the top of the hood and is provided with anairtight connection. The vapors from the lettle pass-thru an inner glass pipe 16 withi the 4condenser which is provided with enlarge-y ments 17 at spaced intervals and'cold water is adapted to circulate in the condenser casing around the vapor pipe.` The cold water casing thru an 'inlet pipe 18 and is discharged from ther top thru an outlet pipe 19. A thermometer 2O 4may extend thru avsuitable pacling in the hood into the i'nuterior of the kett e.

In the form of the invention shown in lFig.'

2 of the drawings, the condenser casing 21 1s provided with an inner glass coil 22 having a depending pipe 23 which extends thru the hood by means of which the vapors pass into the coil. Cold water is circulated thruv the condenser casing yy means of aninlet. pipe )24 and an outlet pipe 25. i

In practicing the process, a quantity of rubber is dissolved in a suitable rubber solvent such as benzol or toluol and allowed tov stand until the rubber becomes softened. The

dissolved rubber is then placed in the kettle 1 and hot or boiling water yis delivered to .the jacket 4 thru the yfeed pipe 5, the mixing valve l6 being rproperly regulated to supply A the water at a desired temperature. Steam llil sol

-may be fed thruthe pipe 7 if necessary to raise the temperature of thecontents of the kettle to the desired value between.100 and 120 C. 'Ihe rubber and solvent are d brought to a boiling state and the Jf'um'es pass into the reiux condenser." As the condensable portion of the fumes or vapor are condensed by the Icold water, they drop back into the kettle; thenon-condensable constituents of the rubber and solvent are discharged to After the contents of the the. atmosphere. j kettle begin to boil the temperature is reduced to approximately '100 C. and the contents of the kettle are maintained at this tempera- 4los ture for from two and one-half to three hours v u to permit'the escape of alarge portion ,of the non-condensable volatile matter and to bring the residue. to the desired liquefied condition. Itjis deslrable to haveall'interconnecting parts of the apparatus. carefully sealed to .prevent accidental entranceof moisture or After preparing the liquefied rubber as above .described I'prefer tocool the liquefied rubber and then mix therewith a cellulose material such as soluble pyroxylin or soluble cotton. What is known as 24 ounce soluble cotton, that is soluble cotton comprising 24 ounces of cotton of cellulosev dissolved in a gallon of solvent, gives verysatisfactory results but it willbe understood that the inven! tion is not limited to the use of'this particul lar form of the cellulose ingredient.

As a'n example of one embodiment of my improved process I may dissolve from 5 to 8 ounces of crude rubber in a quart of benzol 'andadd thereto from 4 to`5 pints ofcarbon tetrachloride. This mixture may be 'boiled from 21/2 to 3 hours at a temperature between I O C. and 1204s C. yAfter the boiled mixture has been cooled, 1/2pint to lpint of pyroxylin;

may

be incorporated with `the mixtura-` L c5 is delivered tothe bottom of the `condenser lWhile boiling the rubber solution the cqfielse maar@ densable volatilized products should be continuously returned to the solution so that the final product will contain the cellulose material and liqueedrubber which contains substantially all the substance of the original crude rubber, except the products driven oli' during the boiling operation in the form of .Y

non-condensable gases. Carbon tetrachloride is employed where it is desirable to produce a product which is less inflammable than the product obtained without the use of such a composition.

It is to be understood that my invention is not confined to the specific embodiments and examples herein described in detail but includes such modifications thereof as fall within the scope of the appended claims.

I claim: v 1. A composition comprising liquefied rubber and pyroxylin, the liquefied rubber containing substantially all of the condensable products obtained upon boiling crude rubber dissolved in a suitable solvent.

v 2. A composition comprising liquefied rubber and pyroxylin, the liqueed rubber containing 'substantially all of the condensable products obtained upon boiling crude rubber dissolved in a suitable solvent, at temperatures between 100 C. and 120 C.A

3. A composition comprising liqueedrubber, pyroxylin, benzol and carbon tetrachloride, the liquefied rubber containing substantially all of the condensable products obtainable upon boiling crude rubber dissolved in a suitable solvent.

l 4. Acomposition comprising nitrocellulose and the reaction products of rubber and a suitable solvent selected-from a group con" sisting of benzol, toluol and carbon tetrachlo- 40 ride, the composition containing substantially all ofthe condensable productslobtainable upon boiling cruderubber dissolved in the solvent at a. temperature between C'and C.

45 p 5. A composition'comprising li ueiied rubber and nitrocellulose, `the lique ed rubber and cellulose material being'in the approximate proportions of `l/2v pint to 1 pint of cellulose material to5 to 8 ounces of liquefedrub- .t0 ber, the liquefied rubber' containing substantially all of the condensable products obtainable upon boiling crude rubber dissolved in a Asuitable solvent. f v

' 6.' A composition comprising liquefied .5 'rubber and nitrocellulose, the liquefied rubbei and cellulose material being inJ the approxlmate proportions of `1/ pint to 1.pint of cellulose material to 2 to 12 `ounces of l 1q ue lied rubber, the liquefied rubber -contaimng .l .55" liubstantially all 'of the condensable roducts ,.v'obtainable upon boiling crude rub er dis- '4 solved in a suitable solvent.'

vlIn testimony whereof I alixmy slgnature.

05 I -HARQLD PAGE BUTLER. 

